Influence of dentin substrates to simplify wet‐bonding: A leakage‐free and reliable tensile strength interface for long‐lasting restorations

Abstract The wet‐bonding procedure can be simplified by eliminating the primer. An aqueous mixture of 1% citric acid and 1% ferric chloride (1‐1) was hypothesized as providing an easier dehydratable thinner substrate to which 4‐META/MMA‐TBB resin can adhere reliably. The 1‐1 was applied for 10 s and rinsed off with water for 10 s. Demineralized dentin under four conditions was prepared before bonding to PMMA rod using 4‐META/MMA‐TBB resin: air‐dried 10 s (D‐NP); air‐dried 10 s, primed 60 s with 5% 4‐META in acetone (D‐P); blotted dry 10 s (W‐NP); blotted dry 10 s, primed 60 s (W‐P). The tensile strengths (MPa) using mini‐dumbbell specimens were 4.0 ± 2.4 for D‐NP, 10.6 ± 5.4 for D‐P, 38.3 ± 4.4 for W‐NP, and 42.9 ± 3.3 for W‐P. There was no significant difference between W‐NP and W‐P with cohesive failure in the dentin and the cured resin. In the wet groups, the hybridized dentin was stable against both HCl and NaOCl challenges. TEM examination and a leakage tests confirmed a perfect seal with a leakage‐free interface of W‐NP. These results suggest that this primer‐less wet‐bonding is promising method to protect the underlying intact dentin and pulp, thus providing long‐lasting dental treatment. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.